RNA is one of the most difficult biomolecules to stabilize as a consequence of both chemical self-hydrolysis and enzyme-mediated degradation. Accordingly, the extraction and preservation of RNA derived from a biological sample is sensitive to a number of environmental factors including but not limited to the buffer used to extract or collect the RNA, pH, temperature, and particularly the ubiquitous presence of robust ribonucleases (RNases). As a result, RNA in both purified and unpurified states has typically required storage at −80° C. to prevent hydrolysis and enzymatic degradation and preserve the integrity of the RNA sample. The capability to extract, collect, and preserve RNA under ambient conditions is economically desirable in order to avoid the costs and space requirements associated with refrigeration or freezing samples at −80° C.
Current methodologies for preserving RNA under ambient conditions in a liquid state have focused on deactivation of RNases through the use of, for example, detergents, chaotropic compounds, reducing agents, transitional metals, organic solvents, chelating agents, proteases, RNase peptide inhibitors, and anti-RNase antibodies. Additional efforts have focused on modifying RNA chemically in order to prevent trans-esterification and self-hydrolysis. Most commercially available RNA preservation products but can only preserve RNA in a liquid state for days or weeks at room temperature. Current technologies that claim successful collection and preservation of RNA in a dry format typically require that the RNA is first “pre-purified” and concentrated from the biological material (e.g., biological samples such as blood, serum, tissue, saliva, etc.) prior to storage of the RNA.
Current technologies for the preservation of RNA in a dry format require additional drying facilities. These methods are therefore not conducive to direct RNA collection from a sample (e.g., a biological sample) without significant sample processing.
Accordingly, compositions and methods that integrate RNA extraction, stabilization, and storage/preservation from a sample (e.g., a biological sample) within a single process are desirable and needed in the art. Such compositions and methods would permit long-term storage of RNA under ambient conditions and allow the intact RNA to be recovered for further analysis.